// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This file defines the type used to provide details for NotificationService
// notifications.

#ifndef CONTENT_PUBLIC_BROWSER_NOTIFICATION_DETAILS_H_
#define CONTENT_PUBLIC_BROWSER_NOTIFICATION_DETAILS_H_

#include <stdint.h>

#include "content/common/content_export.h"

namespace content {

// Do not declare a NotificationDetails directly--use either
// "Details<detailsclassname>(detailsclasspointer)" or
// NotificationService::NoDetails().
class CONTENT_EXPORT NotificationDetails {
public:
    NotificationDetails()
        : ptr_(nullptr)
    {
    }
    NotificationDetails(const NotificationDetails& other)
        : ptr_(other.ptr_)
    {
    }
    ~NotificationDetails() { }

    // NotificationDetails can be used as the index for a map; this method
    // returns the pointer to the current details as an identifier, for use as a
    // map index.
    uintptr_t map_key() const { return reinterpret_cast<uintptr_t>(ptr_); }

    bool operator!=(const NotificationDetails& other) const
    {
        return ptr_ != other.ptr_;
    }

    bool operator==(const NotificationDetails& other) const
    {
        return ptr_ == other.ptr_;
    }

protected:
    explicit NotificationDetails(const void* ptr)
        : ptr_(ptr)
    {
    }

    // Declaring this const allows Details<T> to be used with both T = Foo and
    // T = const Foo.
    const void* ptr_;
};

template <class T>
class Details : public NotificationDetails {
public:
    // TODO(erg): Our code hard relies on implicit conversion
    Details(T* ptr)
        : NotificationDetails(ptr)
    {
    } // NOLINT
    Details(const NotificationDetails& other) // NOLINT
        : NotificationDetails(other)
    {
    }

    T* operator->() const { return ptr(); }
    // The casts here allow this to compile with both T = Foo and T = const Foo.
    T* ptr() const { return static_cast<T*>(const_cast<void*>(ptr_)); }
};

} // namespace content

#endif // CONTENT_PUBLIC_BROWSER_NOTIFICATION_DETAILS_H_
